Robert Ito

The hi-res future of anti-pollution tech

Street View cars map the way to cleaner air, block by block.

In the middle of West Oakland is a community garden where
locals go to tend and sow small but cherished plots of squash, tomatoes,
sunflowers, tree collards, pole beans, and kale. Plump hens take vigorous
dust baths in the chicken coop nearby; honeybees from the garden’s hives and
butterflies fill the air. For residents it’s an urban paradise, with beets.

Right outside, however, semis and concrete mixers and city buses whiz by at a
regular clip. Down the street there’s a salvage yard filled with husks of
cars, and an enormous recycling center where mini-Everests of scrap metal
reach to the sky. Take a whiff in the garden and you’ll get notes of lavender
and sage; on the street, it’s eau de truck exhaust. But if you were
to ask most scientists or neighborhood activists about the air quality in
this stretch of West Oakland, they wouldn’t be able to differentiate from one
block to the next. They’d just tell you it was all lousy.

West Oakland Farm Park

Black carbon:

High

.6 micrograms per m³

Nitric oxide:

Low

6 parts per billion

Nitrogen dioxide:

High

18 parts per billion

Erin Cary, director of advancement for City Slicker Farms, at West Oakland Farm
Park, where kale, squash, and tomatoes grow just a few blocks away from the
perpetual gridlock on Interstate 580.

Until now. Beginning in 2015, a pair of Google Street View cars, equipped
with high tech “mobile labs” developed by San Francisco–based startup Aclima,
crisscrossed the streets of West Oakland taking second-by-second samples of
the area’s air. They tested for nitrogen dioxide and a type of pollution
known as black carbon (bad for your heart and lungs, not to mention the
planet), as well as nitric oxide. The cars hit every stretch of pavement,
from tiny cul-de-sacs to truck-choked Peralta Street, multiple times, taking
millions of measurements.

There are three stationary air pollution monitors for all of Oakland, which
reveal the city’s air quality as a whole. But the Street View cars can tell
you what the air is like at, say, the corner of Market Street and Grand
Avenue—basically anywhere you can drive a Street View car. They can even tell
you how the air varies from one end of a single block to the other for a
truly hi-res view of the problem.The result: one of the largest and most
granular data sets of urban air pollution ever assembled in the world.

“We visited each block on between 20 and 50 different days over the course of
a year,” says Joshua Apte, an engineering professor at the University of
Texas at Austin. In the process, they were able to identify patterns they
wouldn’t have otherwise seen. “If pollution spikes for an instant, it may or
may not be such a bad thing. But if pollution is consistently high, that’s
something we really should care about."

Anatomy of a mobile air pollution detection lab

1. Aclima’s mobile platform is built onto
Google’s existing Street View cars and makes use of their elaborate GPS
tracking and 360-degree cameras.

2. Air is sampled through an inlet on top of the car and pumped into a pollution-monitoring system in the back.

3. Sensors measure substances like black carbon, nitric oxide,
and nitrogen dioxide. Data on pollution levels for that specific
locale are stored on the Google Cloud Platform and made available via Google
Maps and Google Earth.

Project Air View brings together experts of all backgrounds and stripes. The
nonprofit Environmental Defense Fund, which had previously partnered with
Google to map methane gas leaks under city streets, brought Apte from UT
Austin and other researchers together with Google and Aclima. Aclima had
already worked with Google, measuring air pollution in Denver in 2014, before
coming to the San Francisco Bay Area. To date, Aclima and Google have
collected nearly a billion data points in California alone.

Aclima’s detectors are powerful enough to discern the tiniest amounts of
airborne pollutants but small enough to fit inside a Subaru Impreza, and
later in the Hyundai Santa Fes used in the Oakland study. (In the past,
similar mobile monitoring projects in places like Beijing and Helsinki
required large trucks and vans, often navigated by the harried scientists
themselves.) Google provided the Street View cars and drivers, the cloud
infrastructure to store the data, and the platforms (like Google Maps and
Google Earth) to get the word out about the findings.

“The goal is to make this data available to more groups,” says Karin
Tuxen-Bettman, program manager for Google Earth Outreach. “To put it in the
hands of more people and make the invisible visible.”

Karin Tuxen-Bettman, program manager for Google Earth Outreach, wants to make
street-level pollution data as accessible as Google Street View.

The researchers also monitored conditions in neighboring East Oakland and San
Francisco, but West Oakland has been a particular focus of concern. Local
groups like the West Oakland Environmental Indicators Project had long
complained about the area’s air quality. Compared to the rest of Alameda
County, West Oakland had nearly twice the rate of asthma emergency room
visits and higher rates of stroke and congestive heart failure among
residents. Unlike other sections of California, however, where the topography
magnifies the problem—think Los Angeles or the Central Valley—nearly all of
West Oakland’s issues come from local emissions. The neighborhood is ringed
by three busy freeways—the 580, 880, and 980. Trucks rush to and from the
nearby Port of Oakland, while the region itself is a mix of residential and
commercial buildings, where single-family homes butt up against scrapyards
and industrial warehouses.

West Grand near Peralta

Black carbon:

Severe

1+ micrograms per m³

Nitric oxide:

Severe

24+ parts per billion

Nitrogen dioxide:

Severe

24+ parts per billion

By combining location data with pollution sensors, researchers can detect
exactly where pollution levels begin to spike as vehicles on city streets
accelerate to merge onto the interstate.

As the data began to flow in, the researchers made a startling discovery: The
pollution varied not just among cities or neighborhoods, but noticeably and
dramatically from block to block. They also discovered specific points where
the pollution was particularly high. Two of these “hot spots” are within
sniffing distance of West Oakland’s Farm Park, home of all those chickens and
bees and urban farmers; another is right next to the Willie Keyes Community
Recreation Center, named after a beloved neighborhood activist who fought
against, among other things, the region’s unceasing truck traffic. And the
pollution didn’t just vary from block to block. Even on a single street,
concentrations of pollutants could be five to eight times higher on one end
of the block than the other. “In our scientific hearts we thought that might
be the case, that pollution is hyperlocal, but we were still really excited
to see the hot spots,” says Melissa Lunden, chief scientist at Aclima. "And
then it was a matter of, OK, why are they there?"

From these findings, the EDF created interactive maps detailing the
various pollutant levels and hot spots. Zoom in on a stretch of Peralta and
you can see the point where cars speed up to get onto the Bay Bridge (thus
creating more pollution) or where a steady stream of trucks head to and from
the Port of Oakland. Colored dots that range from yellow (least bad) to dark
red (highest concentrations) reveal each area’s pollution levels. “In this
world where everybody’s got more and more data, the key is to be able to
analyze it and move from data to information to knowledge to action,” says
Millie Chu Baird, a senior director at the EDF.

West Oakland residents had nearly twice the rate of asthma-related emergency
room visits as residents of the rest of the county.

News of the study has already reached the community garden. Sitting on a
bench amid plots of sunflowers and strawberries, Erin Cary, the farm’s
director of advancement, describes taking the news—and maps—to her
colleagues. On one map, the area by the salvage yard and recycling center
(and, unfortunately, the farm’s playground) is peppered with dark red dots;
as you move farther away, the dots cool to less-distressing oranges and
yellows. “We’ve known that there are air quality problems, but we hadn’t seen
it on such a microscopic level,” she says. “The air quality in this community
garden is different than down by the playground, but you wouldn’t have any
sense of that without those sorts of mapping tools.”

A block up the street at Willie Keyes, recreation leader Meredith Evans-Moore
is supervising about two dozen kids, many of them playing basketball in the
center’s large gym. She hasn’t seen the maps but isn’t surprised to learn
that her rec center is right next to a hot spot. “We’ve got a lot of
respiratory issues here,” she says. “More and more kids have asthma,
bronchitis.”

Willie Keyes Recreation Center

Black carbon:

Medium

.05 micrograms per m³

Nitric oxide:

Low

6 parts per billion

Nitrogen dioxide:

Medium

12 parts per billion

This rec center in West Oakland is located just a couple of blocks from the
busy Interstate 580 freeway. Meredith Evans-Moore says that her students who
play here seem to have an increasing number of respiratory issues.

Project Air View is an ongoing endeavor, with similar trips taking place
throughout San Francisco, Los Angeles, and the Central Valley. With each new
outing, technological advances are exponentially increasing what people
know—and what they can do with what they know. As next-generation air sensors
become smaller and cheaper, researchers could place them on everything from
city buses to taxis. Intelligent systems will be able to even more accurately
forecast air pollution in real time based on a multitude of factors, from
traffic patterns to that day’s weather to pollution-emitting businesses. “I’m
really excited to apply more machine learning to this data, so that we can
analyze it even faster,” says Tuxen-Bettman.

The maps and accompanying data are a boon to all concerned. Environmental
scientists can take what’s been learned about mobile monitoring and
hyperlocal pollution and apply it to cities and regions around the world with
even worse air problems. On a more personal scale, individuals may someday be
able to pull up an app on their smartphone and see whether it might be better
for their lungs to walk down one street versus another a block over. For
cities, the hyperlocal maps are a nice thing to have if you’re deciding on
investing in a fleet of clean buses and just which areas might benefit from
them the most. As for community organizations, the data is both confirmation
and validation. “A lot of these areas that popped up on the map were areas
that these community groups already knew were problems,” says Tuxen-Bettman.
“They live there in the neighborhood. They see people getting sick. But these
maps could finally prove what they have always suspected.”

ROBERT ITOis a writer based in Los Angeles. He is a
frequent contributer to The New York Times, California Sunday,
and Los Angeles magazine.